The present invention relates to an improved method of synthesizing polyamines, the improvement comprising producing polyamines having an increased nitrogen content. It concerns the improved fuel additives thereby produced, and the resultant improved fuel composition which comprises an admixture of said fuel additive and a gasoline.
It is known that oil soluble polyamines containing at least one olefinic polymer chain or oil soluble polyether can be employed to improve the detergent properties of fuel and lubricant compositions. The use of such compositions, their utility in providing a fuel with significantly reduced octane requirement increase (ORI) characteristics; removal and/or beneficial modification of deposits in the combustion chamber, intake valves and the like; as well as potential improvement in fuel efficiency are taught by a number of prior patents including U.S. Pat. Nos. 3,275,554; 4,438,757; 3,565,804; 3,574,576; 3,898,056; 3,960,515; 4,022,589; and 4,039,300, the disclosures and claims of all of which are specifically incorporated herein by reference. Such polyamines have been used both alone and in combination with other additives, particularly polymeric additives.
Polyolefinic or polyether amine fuel detergents are composed primarily of two components; a hydrophile (amine) and a long chain hydrocarbyl or oxyalkylene hydrophobes (polymer). The hydrophile portion, typically amines, contain from one to greater than five nitrogen atoms. The hydrocarbyl or oxyalkylene hydrophobe is typically a long chain (500-5,000 molecular weight) polymer offering thermal stability and fuel solubility to the detergent.
The detergent molecule is synthesized through a variety of unique processes. For fuel additive applications the desired reaction for maximum cost performance is 100% utilization of reaction component, reacting one polymer molecule with one amine molecule to create a monomeric product. However, many processes are designed for or are limited to 65% monomer when amines containing multiple reactive moieties are utilized. The remaining polymer either does not react or over reacts to dimer or higher homologs (i.e. molecules containing two or more polymer molecules attached to one amine molecule).
In every process, the polymer is first reacted, modified, conditioned or combined with specific reaction components to promote the reaction with an amine. Polymers and amines will not react without the intermediate step.
Various conversion processes for creating polyamines are described in the prior art. For example, U.S. Pat. Nos. 3,275,554; 3,864,098; 3,565,804; 3,753,670; 3,822,209; 3,869,514; 4,438,757 and 5,346,965 all relate to the following conversion of polyisobutene (PIB) to PIB-amine.